The individual processing steps of conventional metal finishing processes are often performed at separate work stations, each station usually including a specialized piece of equipment. For example, in batch plating processes, parts to be plated are brought to a loading station where the parts are loaded into a metal finishing container often called a "barrel". After loading, the barrel is engaged by a conveyor system such as a return barrel machine or programmed hoist which carries the loaded barrel through the "wet" steps of the plating process. At the conclusion of this portion of the process, the parts are unloaded from the barrel and transferred to a drying station which may include a centrifugal dryer to provide the requisite drying. At the conclusion of this drying step, parts are usually transferred to a shipping station from where the finished parts are forwarded to the customer.
In general, the parts are transferred between the processing stations by conveyors or by means of special transfer containers such as wire mesh or perforate sheet metal baskets which are typically attached to and transported by an overhead hoist system. In the latter transfer method, operators are needed to load and unload the parts baskets, one or more times during the process.
It is desirable to automate as much of the metal finishing process as possible to not only reduce labor cost, but also to minimize personnel exposure to the processing chemistry. Additionally, the production rate and efficieny of a metal process can often be a function of a skill and motivation of the operators. Oftentimes, the productivity is reduced by interruptions such as coffee breaks, sickness, lunches, shift changes and operator fatigue.
In all but the most advanced metal finishing plants, the parts to be processed are manually loaded into the metal finishing barrel at the commencement of the process, and then are manually unloaded from the barrel into other machines such as dryers at the conclusion of the process. The transfer of parts between the various stations is not only fatiguing to an operator but exposes the equipment to potential damage by a careless operator.
In the more advanced metal finishing plants, attempts at automating the parts transferred between the stations have been made. Typically, belt conveyors, skip loaders, etc. are used to facilitate the transfer, but nevertheless, some operator effort is still needed even in the most advanced processes. Additionally, the use of multiple conveyors for transferring the parts from the plurality of machines which typically form the total metal finishing process, can be costly to purchase and maintain.